2004 V40 front end vibration at 40-50MPH

Just as a starting point, any ideas on what are most frequent causes of front end vibration when accelerating from 40mph to 50mph? I have recently replaced stabilizer bushings and engine mounts. After, had wheels aligned and tires balanced to rule that out.

Still experiencing some relatively heavy vibration/shimmy during acceleration after 40mph. Seems to stop at speeds above 50mph.